Robot for handling

ABSTRACT

A robot for handling comprises at least four bosses (20a, 20b, 20c, 20d) coaxially provided and displaced from each other axially of the center of rotation to permit independent rotation, arms (21a, 21b, 21c, 21d) provided on the bosses, respectively, links (22a, 22b, 22c, 22d) connected to the respective arms, a plurality of carriages (8a, 8b) connected through a carriage attitude regulating mechanism (B) to tip ends of each pair of links, each of which is connected to each arm of each pair of axially adjacent two bosses, the plurality of carriages being displaced from each other axially of the center of rotation, and independent drive sources (27a, 27b, 27c, 27d), respectively, connected to each of said bosses.

TECHNICAL FIELD

The present invention relates to a handling robot in a multiple chambertype manufacturing system such as a semiconductor manufacturing systemand an LCD manufacturing system, in which a plurality of processchambers are disposed around a single transfer chamber to constitute alike plurality of stations, and in which a workpiece in the form of athin plate such as a wafer that is to be machined and processed in eachof the process chambers is, in a clean state or an evacuated (lowpressure) state, conveyed by the said handling robot that is arranged inthe transfer chamber, via the said transfer chamber from one of the saidprocess chambers to another.

BACKGROUND ART

A multiple chamber type semiconductor manufacturing system isconstructed as shown in FIG. 1 of the drawings attached hereto and has aplurality of process chamber stations 2a, 2b, 2c, 2d and 2e disposedaround a transfer chamber 1 and also has arranged therein a pair ofworkpiece delivery stations 3 by each of which the workpiece isdelivered to an outside thereof, and in which the space within thetransfer chamber 1 is kept in an evacuated state by a suction unit.

And, the above mentioned transfer chamber 1 is constructed as shown inFIG. 2 of the drawings attached hereto and has a handling robot Aprovided at a central region thereof so as to be rotatable. It also isprovided with a plurality of partition walls 5 that serve as theperipheral walls thereof with each wall opposing to each of the saidstations 2a, 2b, 2c, 2d and 2e and the said workpiece delivery stations3 and in which there are also provided a plurality of gates 56 each ofwhich constitutes both an inlet and an outlet for the workpiece to befed into and out of each of the said stations. Each such gate 6 isconfigured so as to be opened and closed by an opening and closing door(not shown) that is disposed in opposition to each of the said gates 6.

As the above mentioned handling robot A, there has hitherto been used anapparatus of so called flog leg type with a pair of arms and itsconstruction is as shown in FIGS. 3 to 7 of the drawings attachedhereto.

In this construction, the said pair of arms, designated at 7a and 7b, ofan identical length are arranged so as to be rotatable about a center ofrotation. On the other hand, there are provided a pair of transfertables 8a and 8b that have their respective bases, to each of which isconnected one end of each of two legs of each of a pair of links 9a and9b of an identical length, respectively. The said one end of each of thesaid two legs of each of the both links 9a and 9b is coupled via a flogleg type transfer table attitude regulating mechanism to each of thesaid transfer tables 8a and 8b, respectively, so that the said links 9aand 9b may be rotated in a pair of directions each of which iscompletely symmetrical with respect to the said transfer tables 8a and8b.

And, one of the pair of links 9a and 9b which are coupled to the saidtransfer tables 8a and 8b is coupled to one of the said pair of arms 7aand 7b whereas the other of the said links 9a and 9b is coupled to theother of the said arms 7a and 7b, respectively.

FIG. 4A in the drawings attached hereto shows the said transfer tableattitude regulating mechanism B of the above mentioned flog leg type, inwhich the respective forward end portions of the said links 9a and 9b inthe pair which are coupled to the said transfer tables 8a and 8b arecoupled together in a gear configuration that comprises a pair of gears9c and 9c which mesh with each other so that the angles of attitude θ Rand θ L of the said links 9a and 9b with respect to the said transfertables 8a and 8b may always be identical to each other. This allows eachof the said transfer tables 8a and 8b to be always oriented in a radialdirection and operated in the radial direction.

It should be noted, however, that the above mentioned links 8a and 9bmay not necessarily be coupled together in a gear arrangement, but mayalternatively be coupled together with a crossed belting arrangement 9aas shown in FIG. 4B of the drawings attached hereto.

FIG. 5 of the drawings attached hereto shows a mechanism for permittingthe above mentioned arms 7a and 7b to be rotated independently of eachother.

The respective bases of said arms 7a and 7b are each configured in theform of a ring shaped boss and such ring shaped bosses 10a and 10b areconfigured so as to be coaxial about the said center of rotation and tobe rotatably supported with respect to a frame 1a of the said transferchamber 1.

On the other hand, the said ring shaped bosses 10a and 10b have a pairof disk shaped bosses 11a and 11b disposed therein, respectively,wherein a said ring shaped boss and a said disk shaped boss are opposingto each other and arranged so as to be coaxial with each other. A firstpair of said mutually opposing ring shaped and disk shaped bosses and apair of the said mutually opposing ring shaped and disk shaped bossesare coupled and decoupled with each other via each of magnetic couplings12a and 12b, respectively, in each of the directions of rotation.

The above mentioned pair of the disk shaped bosses 11a and 11b havetheir respective rotary shafts 13a and 13b which are arranged so as tobe coaxial with each other. The said rotary shafts 13a and 13b arecoupled to the output sections of a pair of motor units 14a and 14b,respectively, which are coaxial with the said frame 1a of the transferchamber 1 and are supported with their positions deviated in their axialdirection.

The above mentioned motor units 14a and 14b have each integrally coupledthereto a motor 15 which comprises, for example, an AC servo motor and aspeed reduction gear 16 which comprises, for example, a Harmonic Drive(trade name, identically referred to hereinafter). Such reduction gears16 and 16 have their output sections which are coupled to the respectivebases of the said rotary shafts 13a and 13b, respectively.

Since the space within the said transfer chamber 1 in which the arms 7aand 7b are positioned is held in an evacuated state, there is provided asealing partition 17 each between the said ring shaped boss 10a and thesaid disk shaped boss 11a and between the said ring shaped boss 10b andthe said disk shaped boss 11b of the present arm rotary mechanism.

FIGS. 7A and 7B show an operation of the above mentioned handling robotA. As shown in FIG. 7A, when the said two arms 7a and 7b are located ata pair of diametrically symmetrical positions, respectively, withrespect to the said center of rotation, the said links 9a and 9b will bein a state in which they assume their most expanded positions withrespect to each of the said transfer tables 8a and 8b so that the lattermay both be displaced toward the said center of rotation.

In this state, by rotating the said two arms 7a and 7b in an identicaldirection, it can be seen that the said two transfer table 8a and 8bwill be rotated about the said center of rotation whilst maintaining theradial positions thereof.

Also, by rotating the said two arms 7a and 7b in the directions in whichthey may approach towards each other (or in the mutually oppositedirections), from the state shown in FIG. 7A, it can be seen that one ofthe said transfer tables 8a that is located at such a position that theangle made by the said two arms 7a and 7b is reduced will be pushed bythe said links 9a and 9b so as to be projected in its radially outwarddirection so that it may be thrusted into one of the above mentionedstations 2a, 2b, 2c, 2d, 2e and 3 which are disposed adjacent to theradially outward side with respect to the said transfer chamber 1 asshown in FIG. 7B.

At this point of time, whilst the other of the said transfer tables willbe displaced towards the said center of rotation, it can be seen thatits amount of displacement will be small because of an angle that ismade between the said arms 7a and 7b and an angle that is made betweenthe said links 9a and 9b.

The above mentioned conventional handling robot has been expected toprovide a functional effect as a two arm robot by virtue of theadvantage that a pair of transfer tables are provided and canalternately or consecutively be used for each of a variety of stations.It has been found, however, that as a matter of reality there arises thefollowing problem

More specifically, since each of the said pair of the transfer tables iscoupled via a pair of links commonly to a pair of arms, respectively, ithas been found that when one transfer table is displaced towards astation, the other transfer table must necessarily be in a stand-bystate and that this will make it impossible for an individual transfertable to be displaced optionally towards a station.

Also, in a case where a transfer table is to be rotated, a pair oftransfer tables must be rotated together and this makes it impossiblefor an individual transfer table to be rotated as desired.

From the reasons mentioned above, in spite of the fact that there havespecially been provided a pair of transfer tables, it is found that sucha provision itself almost has not contributed to a desired shortening ofthe time cycle in a semiconductor manufacturing system that has beenprovided with a plurality of process chambers around a transfer chamber.

Also, in the above mentioned conventional handling robot, it is notedthat a drive mechanism for rotating each of the said arms is constitutedwith a pair of the said motor units 14a and 14b, each of which combinesthe said motor 14 with a said speed reduction gear 16 that is high inthe ratio of speed reduction. Since such speed reduction gears 16 and 16of the said motor units 14a and 14b have their output sections which areconnected via a pair of the said rotary shafts to a pair of the saiddisk shaped bosses 11a and 11b, it has been found that there must be anelongated path of power transmission provided from each of therespective output sections of the said speed reduction gears to acorresponding one of the said disk shaped bosses.

It may also be noted that although as shown in FIG. 6 of the drawingattached hereto there has been another construction of the handlingrobot in which a pair of disk shaped bosses 11a' and 11b' are providedinteriorly with a pair of inner teeth gears 11c and 11d, respectively,with which a pair of pinion gears 13c and 13d mesh, respectively, thatare securely fixed to a pair of rotary shafts 13a' and 13b' which inturn are coupled to the speed reduction gears of the said motor units14a and 14b, respectively, such a construction again requires that thereshould be provided an elongated path of power transmission from each ofthe respective output sections of the said speed reduction gears to acorresponding one of the said disk shaped bosses.

In the drive mechanism of the conventional handling robot, the need foran elongated path of power transmission from a motor unit to a diskshaped boss as noted above has resulted in an insufficiently lowtorsional rigidity. Also, since a transmission torque is increased at aspeed reduction gear that is remote from a disk shaped boss via a rotaryshaft, a deformation thereof may give rise to an error in rotationthereof which as it is produces an error in rotary angle of an arm, thushaving constituted a bottle neck in accurately controlling the rotaryangle of the handling robot in the prior art.

It may also be noted that a handling robot to be used in a clean room oran evacuated state in an above mentioned semiconductor manufacturingsystem requires that a dust should be introduced therein at a veryminimum so that no foreign matter may adhere to an object beingconveyed.

In a conventional handling robot as generally mentioned above andparticularly as shown in FIG. 8 of the drawings attached hereto, inwhich a transfer table 8 that enters into and comes out of each of thesaid stations 2a-2e via a said gate 6 is coupled to a pair of the saidarms 7a and 7b via the said transfer table attitude regulating mechanismB of a flog leg type having a pair of rotary nodes, however, it has beenfound that there arises the problem that a portion of a geartransmission mechanism or a belt transmission mechanism which isincluded to constitute the said transfer table attitude regulatingmechanism B may be a source of dusts from which a dust can develop. Afurther problem has been that such a portion also tends to be loosened,giving rise to a positioning inaccuracy.

Accordingly, the present invention has been made with the foregoingproblems taken into account, and has for its generic object to provide ahandling robot whereby the cycle time for a manufacturing operation canbe shortened by permitting an action for conveying each of a pluralityof transfer tables into and out of each of the stations and an actionthereof to be carried out independently of each other as desired whereasthe accuracy at which an arm is controlledly rotated can be enhanced bypermitting any error within the path of power transmission not toinfluence the control of the rotary angle of the said arm.

A further important object of the present invention is to provide ahandling robot whereby a dust that may be produced at a coupling portionbetween a transfer table and an arm can be reduced at a very minimum andany loosening that may develop at the said portion can also be reducedat a very minimum.

SUMMARY OF THE INVENTION

In order to achieve the object mentioned above, there is provided inaccordance with the present invention, a handling robot which is soconfigured that at least four bosses may be disposed in a transferchamber so as to be coaxial to one another and rotatable independentlyof one another and to be deviated in their positions towards the axis ofa center of rotation; each of the said bosses may be provided with anarm, respectively; a link may be coupled to each of such arms,respectively; two of the said bosses which are adjacent to each other inan axial direction may be constituted in a pair; a transfer table may becoupled via a transfer table attitude regulating mechanism to therespective leading ends of each pair of such links which are in turncoupled to each arm of the said pair of the bosses to provide aplurality of such transfer tables which are arranged so as to bedeviated in their positions towards the said axis of the center ofrotation; and an independent drive source may be coupled to each of thesaid bosses, respectively.

And, by rotating the said pair of bosses oppositely to each other tocause a pair of arms coupled thereto in their respective directions inwhich they approach each other, a said transfer table will be allowed toproject in its radial direction via the links coupled to the said pairof the arms. Also, by causing the said pair of the arms to be rotated intheir respective directions in which they depart from each other, thesaid transfer table will be moved so as to be sunk or retracted.

Also, by permitting the said pair of the bosses to rotate in anidentical direction, a said transfer table will be rotationally drivenwhile maintaining its radial position.

The arms and links which individually constitute the said pairs havetheir respective lengths which are identical to each other, with suchtwo arms and two links being so with respect to a single such transfertable. It should be noted, however, such arms and links as with respectto mutually different such transfer tables need not to be of anidentical length in each individual pair. In this case, it can be seenthat their transfer displacement should be variant for differenttransfer tables.

As mentioned above, it can be noted that according to a handling robotprovided in accordance with the present invention, each individualtransfer table may, regardless and independently of other transfertables, perform a workpiece transfer operation between a transferchamber and each of a variety of stations as well as a workpiecetransfer operation in a rotary direction within the transfer chamber.

Accordingly, it can be appreciated that a handling robot according tothe present invention, as it is installed in a semiconductormanufacturing system, may fully perform a variety of functional effectsas a multiple arm (double arm) robot that can serve as a means fortransferring a workpiece in a multiple chamber type manufacturingsystem, and will drastically shorten the cycle time of a workpiecetransfer operation.

Also, in the construction mentioned above, a handling robot according tothe present invention can be so constituted that a first boss sectionthat comprises a first pair of the bosses arranged in the said axialdirection and a first pair of drive units respectively coupled to thesaid bosses may be separately configured from a second boss section thatcomprises a second pair of the bosses arranged in the said axialdirection and a second pair of drive units coupled respectively to thesaid bosses; the said first and second boss sections may be arranged soas to be opposing to each other and in such a manner that the saidbosses may be made coaxial with one another; and the said plurality ofthe transfer tables may be arranged between the said first and secondboss sections so as to be deviated in their positions towards the saidaxis of the center of rotation.

Thus, in the construction in which the said first boss section thatcomprises the said first pair of the bosses arranged in the said axialdirection and the said first pair of drive units respectively coupled tothe said bosses is separately configured from the second boss sectionthat comprises the said second pair of the bosses arranged in the saidaxial direction and the said second pair of drive units respectivelycoupled to the said bosses, it will be seen that a transfer table inthese boss sections can be arranged between them.

And, according to the above mentioned construction, it can be seen thatthe boss sections for driving the respective ones of a pair of transfertables, respectively, can be made individual and, by positioning theseboss sections so as to be spaced apart from each other, a transfer tablemay be disposed between them, and that thus such a transfer table may bemade larger in its sinking direction.

In the above mentioned construction, it is possible that inside of thesaid bosses which are ring shaped, there may be different bosses whichare disk shaped and are supported by a frame of the transfer chamber soas to be the said disk shaped bosses and each of the said ring shapedbosses may be coupled together via a magnetic coupling so as to becoupled and decoupled with each other in a rotary direction; each of thesaid disk shaped bosses may be provided inside thereof with a speedreduction gear; the said reduction gear that is provided inside of eachsuch disk shaped boss may have an input member thereof to which iscoupled a rotary shaft, respectively; such rotary shafts may be arrangedso as to be coaxial with one another about the said center of rotationand so as to extend towards one side of the said axis of the center ofrotation; and each of the said rotary shafts may be coupled to a motor,respectively.

According to the construction mentioned above, it can be seen that arotation of the said drive source which causes a rotation of each of thesaid disk shaped bosses will be transmitted via the said rotary shaft tothe said speed reduction gear whose output will be directly transmittedto a said disk shaped boss. It can also be seen that a said ring shapedboss will, by permitting the said disk shaped boss that is disposedinside of the said ring shaped boss to be rotated by the said drivesource via the said speed reduction gear, be rotated via the saidmagnetic coupling.

And, according to the construction mentioned above, it can further beenseen that by permitting an output member of the said speed reductiongear to be directly coupled to a drive member for rotationally driving asaid arm, an error in the angle of rotation that occurs until it arrivesat a said drive unit from a prime mover over a said rotary shaft and asaid reduction gear will be transmitted as it is reduced by a reductiongear ratio of the said speed reduction gear. As a result, any influenceof an error in the angle of rotation prior to its arrival at the saidspeed reduction gear can be drastically reduced. This may allow a powerof rotation to be transmitted without transmitting such an error in theangle of rotation from the said speed reduction gear up to a said diskshaped boss; hence an enhancement in the accuracy in the control of arotary angle of a said arm will be ensured.

In the above mentioned construction, it is possible that such motors maybe disposed in parallel to one another around the said center ofrotation of the said disk shaped bosses; and each of the said motors andeach of the said rotary shafts may be coupled together by a powertransmission means such as a timing belt.

Alternatively, it is also possible that such motors may be disposed inseries with one another in the direction of the said axis of the centerof rotation of the said disk shaped bosses; and each of the said motorsmay have an output member thereof that is directly coupled to each ofthe said rotary shafts, respectively.

According to such a construction as mentioned above, it will be seenthat the above mentioned motors which constitute the respective primemover sources for the said plurality of the arms can be selectivelyarranged in the frame, i. e. either in parallel to one another aroundthe said center of rotation or in series with one another along the saidcenter of rotation, in accordance with a particular frame constructionemployed for the transfer chamber.

Furthermore, in the above mentioned construction, it is possible that atleast one of the said plurality of the transfer tables may be renderedcapable of being displaced towards the said axis of the center ofrotation.

It is also possible that at least one pair of the said bosses which arering shaped and the said drive units for driving the said at least onepair of the ring shaped bosses may be rendered capable of beingdisplaced towards the said axis of the center of rotation.

Also, it is possible that a pair of the said ring shaped bosses whichare coupled to at least one of the said plurality of the transfer tablesand a pair of the said disk shaped bosses which are positioned inside ofthe said pair of the ring shaped bosses may each be supported so as tobe displaceable towards the said axis of the center of rotation; each ofthe said ring shaped bosses and each of the said disk shaped bosseswhich are opposing to each other may be coupled together by a magneticcoupling such as that of a linear rotary type which is made capable oftransmitting both a force of rotation and a force of straightadvancement in an axial direction; and the said inside positioned pairof the disk shaped bosses may be coupled to a linear actuator fordisplacing the said pair of the disk shaped bosses.

It is also possible that at a section at which a said transfer table anda said link coupled to the said transfer table are coupled together,there may be provided a displacement mechanism for displacing the saidtransfer table towards the said axis of the center of rotation withrespect to the said link.

It is also possible that at a section at which a said link and a saidarm are coupled together, there may be provided a displacement mechanismfor displacing the said link towards the said axis of the center ofrotation with respect to the said arm.

According to a construction as mentioned above, it can be seen that byallowing the position of a said transfer table in the axial direction ofthe said center of rotation to lie at the position of a said gate, thesaid transfer table will be selectively opposed to the said gate whenthe said transfer table is operatively projected into any one of thesaid stations, thereby permitting the height of the said gate of thetransfer chamber to be in coincidence with the height of a single one ofthe transfer tables. The sealing ability by way of an opening andclosing door for the said gate is thereby improved.

And, especially in the construction in which the above mentioneddisplacement mechanism is provided, it can be noted that since adisplacement towards the said axial direction is effected closer to thesaid leading ends than a said transfer table or a said arm, its mass ofdisplacement may be made smaller.

In the construction mentioned above, it is possible that a said bosssection including a said drive unit may be supported so as to bedisplaceable towards the said axis of the center of rotation withrespect to the said frame; and a said linear actuator may be coupled tothe said boss section.

According to the construction mentioned above, it can be seen that bypermitting the entire handling robot to be moved up and down withrespect to the said frame, the structure of such a driving section canbe vastly be simplified.

In the construction mentioned above, it is possible that at least one ofthe said first boss section and the said second boss section may besupported so as to be displaceable towards the said axis of the centerof rotation with respect to the said frame; and a said linear actuatormay be coupled to the said at least one boss section.

According to the above mentioned construction, it will be seen thatsince the handling robot can be divided into two separate portions, itmay be sufficient for an individual displacement unit to be reduced insize.

In the construction mentioned above, it is possible that each of a saidring shaped boss and a said disk shaped boss which are opposing to eachother via a said magnetic coupling may be rendered capable of beingdisplaced towards the said axis of the center of rotation; a pair ofboss sections of the said disk shaped bosses which are adjacent to eachother in the said axial direction may be coupled together by a saidspeed reduction gear; a cam ring may be provided coaxially with each ofthe said disk shaped bosses of the said boss sections; a cam engagementmember that is provided for each of the said disk shaped bosses may beengaged with a cam portion that is provided in the said cam coupling;and the said cam may be configured so that when the said pair of thedisk shaped bosses are rotated oppositely to each other, they can bedisplaced as a whole towards the said axial direction.

According to the construction mentioned above, it can be seen that forthe reason that an actuator needs not be provided for effecting adisplacement in the said axial direction, and the number of control axesmay be small, a control program can be drastically simplified.

Furthermore, in the construction mentioned above, it is possible that ata section at which a said link and a said arm are coupled together,there may be provided a cam shaft having a cam portion and a camengagement member fitted with the said cam portion so that they can becoupled to one of the said link and the said arm; and the said camportion may be so configured that when each pair of the said arms arerotated in their respective directions which are opposite to each other,the said pair of the links can be displaced towards an axially identicaldirection.

According to the above mentioned construction, it can be seen that bypermitting an axial displacement of a said link with respect to a saidarm to be performed so that they may be relatively rotated, an actuatorfor the purpose of such a displacement will become needless and yet acontrol program can vastly be simplified.

In order to attain another object noted previously, there is provided inaccordance with the present invention, a handling robot in which thereare provided at least two bosses so as to be coaxial with each other andto be rotatable independently of each other and so that they may bedeviated in their positions towards the axis of a center of rotation,each of the said bosses is provided with an arm that is coupled to oneof links, a transfer table is coupled to the leading ends of a pair ofthe said links, and an independent drive source is coupled to each ofthe said bosses, the handling robot being so configured that one of thesaid pair of the links and the said transfer table are integrallystructured; and the other of the said pair of the links is coupled tothe said transfer table via a rotary node.

According to the construction mentioned above, it can be seen that bypermitting the said pair of bosses to be rotated oppositely to eachother to allow them to be rotated in their respective directions inwhich they approach each other, a transfer table will be allowed toproject into a desired one of the stations by the transfer chamber viathose links which are coupled to said pair of the arms. Also, bypermitting the said pair of arms to be rotated in their respectivedirections in which they depart from each other, the transfer table willbe moved so as to be sunk.

Then, it can be seen that since the transfer table is structuredintegrally with one of the said links, its attitude when projected orsunk may not be constant and it will be displaced while drawing atrajectory in which its attitude may follow the attitude of the abovementioned one link. Accordingly, the said pair of the arms can becontrolled with respect to their angles of rotation so that the saidtransfer table may be projected and sunk while permitting it to follow apredetermined trajectory passing through a said gate.

According to the construction mentioned above, it can be seen that byallowing a coupling between a said transfer table and a link assembly tobe effected at a said rotary node, a dust may be much less produced muchless frequently at a section at which the said transfer table and thesaid link assembly are coupled together. It should also be noted thatsince the number of such rotary nodes is reduced by one, a looseningthat may occur at a rotary node can be minimized.

BRIEF EXPLANATION OF THE DRAWINGS

The present invention will better be understood from the followingdetailed description and the drawings attached hereto showing certainillustrative embodiments of the present invention. In this connection,it should be noted that such embodiments as illustrated in theaccompanying drawings are intended in no way to limit the presentinvention, but rather to facilitate an explanation and understandingthereof.

In the accompanying drawings:

FIG. 1 is a top plan view diagrammatically showing a semiconductormanufacturing system that constitutes an example of a multiple chambertype manufacturing system;

FIG. 2 is a decomposed perspective view illustrating the relationshipbetween a transfer chamber and a conventional handling robot;

FIG. 3 is a perspective view illustrating the conventional handlingrobot;

FIGS. 4A and 4B are explanatory views, each showing a transfer tableattitude regulating mechanism;

FIG. 5 is a cross sectional view illustrating an arm rotary mechanismfor the conventional handling robot;

FIG. 6 is a cross sectional view illustrating another arm rotarymechanism for the conventional handling robot;

FIGS. 7A and 7B are each a functional explanatory view of theconventional handling robot;

FIG. 8 is a decomposed perspective view illustrating a relationshipbetween a transfer chamber and another conventional handling robot;

FIG. 9 is a cross sectional view illustrating an arm rotary mechanism ofa certain embodiment of the handling robot according to the presentinvention;

FIG. 10 is a front view, partly cut away, showing the handling robotaccording to the present invention;

FIG. 11 is a functional explanatory view showing the handling robotaccording to the present invention;

FIG. 12 is an explanatory view showing a state in which a plurality ofmotors are arranged in parallel to one another;

FIG. 13 is an explanatory view showing a state in which a plurality ofmotors are arranged in series with one another;

FIG. 14 is a cross sectional view showing a construction in which onetransfer table is rendered capable of being displaced towards thecentral axis of rotation;

FIG. 15 is a cross sectional view showing the construction in which thewhole of the bosses is rendered capable of being displaced towards thecentral axis of rotation;

FIG. 16 is a cross sectional view showing the construction in which thewhole of the bosses is rendered capable of being displaced towards thecentral axis of rotation;

FIG. 17 is a cross sectional view showing the construction in which thewhole of the bosses is rendered capable of being displaced towards thecentral axis of rotation;

FIG. 18 is a cross sectional view taken along the line XVIII--XVIII inFIG. 17;

FIG. 19 is a developed explanatory view showing the essential part of anexample shown in FIG. 17;

FIGS. 20A and 20B are each a functional explanatory view showing aconstruction in which a transfer table is rendered capable of beingdisplaced towards the central axis of rotation;

FIG. 21 is a functional explanatory view showing a construction in whicha transfer table is rendered capable of being displaced towards thecentral axis of rotation;

FIG. 22 is a cross sectional view showing a mechanism for displacing alink with respect to an arm in the axial direction;

FIG. 23 is a cross sectional view showing another mechanism fordisplacing a link with respect to an arm in the axial direction;

FIG. 24 is a top plan view showing an example of the construction inwhich the boss section is divided in the axial direction;

FIG. 25 is a front view showing an example of the construction in whichthe boss section is divided in the axial direction;

FIG. 26 is cross sectional view showing one of individual bosses intowhich the boss section in divided in the axial direction;

FIG. 27 is a cross sectional view showing an example in which the bosssection is divided in the axial direction into individual bosses whichare rendered capable of being displaced in the axial direction;

FIG. 28 is a front view showing an example in which the boss section isdivided in the axial direction into individual bosses which are renderedcapable of being displaced in the axial direction by using a cammechanism;

FIG. 29 is a cross sectional view showing one part of the boss sectionshown in FIG. 28;

FIG. 30 is a top plan view showing another embodiment of the handlingrobot according to the present invention; and

FIG. 31 is an explanatory view illustrating the sizes and the angles ofrotation of an arm and a link with respect to a transfer table.

BEST MODES FOR CARRYING OUT THE INVENTION

Hereinafter, suitable embodiments of the present invention with respectto a handling robot will be set forth with reference to the accompanyingdrawings hereof.

A detailed explanation will now be given of a certain embodiment of thepresent invention with reference to FIGS. 9 through 29. In theexplanation of the present embodiment, it should be noted that the samereference numerals and characters individually or in combination as usedin the description of the prior art designate the same components orparts in FIGS. 1 to 7. It should also be noted that the presentembodiment is intended to make use of a pair of transfer tables.

A transfer chamber 1 has a central region in which four ring shapedbosses 20a, 20b, 20c and 20d are supported coaxially with one other andeach rotatably in a state in which they are stacked successively from alower side thereof. And, each of the said ring shaped bosses is providedwith a corresponding one of four arms 21a, 21b, 21c and 21d which havean identical length, respectively.

The second arm 21b and the third arm 21c located in a mid region arebent downwards and upwards, respectively. The leading end of the saidsecond arm 21b is located at the same level as that of the first arm 21ain the axial direction of their center of rotation whereas the leadingend of the said third arm 21 is located at the same level as that of thefourth arm 21d in the axial direction of the said center of rotation.

And, a pair of links 22a and 22b which are coupled to the respectiveleading ends of the said first and second arms 21a and 21b,respectively, are coupled to a single transfer table 8a via a transfertable attitude regulating mechanism of a flog leg type. Also, a pair oflinks 22c and 22d which are coupled to the respective leading ends ofthe said third and fourth arms 21c and 21d, respectively, are similarlycoupled to a single transfer table 8b via such a transfer table attituderegulating mechanism.

Then, by rotating the said first, second, third and fourth ring shapedbosses 20a, 20b, 20c and 20d so as to cause the said first and secondarms 21a and 21b to be rotated in their respective directions in whichthey approach each other, it can be seen that as with what has beendescribed with reference with the prior art, the said transfer table 8awhich is coupled with the said first and second arms 21a and 21b will beprojected radially outwards of the said transfer chamber 1. Also, if thefirst and second arms 21a and 21b are caused to rotate in theirrespective direction in which they depart from each other, the abovementioned transfer table 8a will be moved so as to be sunk or retractedradially inwards of the said transfer chamber 1.

On the other hand, if the said pair of the arms 21a and 21b are rotatedin an identical direction, the said transfer table 8a will be rotated intheir direction of rotation while maintaining its radial position.

Such an operation should be performed in an entirely same manner as theabove with the said third and forth arms 21c and 21d.

And, in such an operation in which one pair of the said first and secondarms 21a and 21b and the other pair of the third and fourth arms 21c and21d are each rotated in a state in which they are spaced apart from eachother in their vertical direction (i. e. in the axial direction of thesaid center of rotation) and hence do not interfere with each other, thetwo transfer tables 8a and 8b which are coupled with the said one andother pairs of the arms, respectively, will be operated independently ofeach other as desired with respect to the said projection, retractionand rotation, individually.

In an inside in which the above mentioned ring shaped bosses 20a, 20b,20c and 20d are opposing to one another, four disk shaped bosses 23a,23b, 23c and 23d are supported by a frame 1a of the said transferchamber 1 so as to be each rotatable in a state in which they are laidone above another in their axial direction.

And, each of the said ring shaped bosses 20a, 20b, 20c and 20d and eachof the said disk shaped bosses 23a, 23b, 23c and 23d which are opposingto each other are coupled together by each of four magnetic couplings24a, 24b, 24c and 24d, respectively, and also so decoupled, in a rotarydirection thereof.

In the above mentioned construction, it should be noted that in order tomaintain the interior of the said transfer chamber 1 in an evacuatedstate, a sealing partition wall 17 is provided between the said ringshaped bosses and the said disk shaped bosses. It should also be notedthat in place of the above mentioned magnetic couplings 24a to 24d,there may be used a magnetic fluid seal (i. e. a ferro-seal thatcontains a permanent magnet).

Inside of the above mentioned disk shaped bosses 23a to 23d, four speedreduction gears 25a, 25b, 25c and 25d are incorporated, respectively.Each of the said speed reduction gears, in view of the requirements thatit should be incorporated within a said disk shaped boss, a space thatis extremely limited, and that it should produce an extremely high ratioof speed reduction, has made use of a Harmonic Drive, supra, of a flattype that consists of a wave generator a, a flex spline b and a pair ofcircular splines c and d, which has hitherto been used widely.

Four rotary shafts 26a, 26b, 26c and 26d are coupled to the respectiveinput members of the said speed reduction gears 25a to 25d,respectively. The said rotary shafts are disposed coaxially with oneanother, of which the first, second and third rotary shafts 26a, 26b and26c are hollow and fitted in and coaxially with one another. Thus, thesecond rotary shaft 26b is fitted in the first rotary shaft 26a, thethird rotary shaft 26c is fitted in the second rotary shaft 26b and thefourth rotary shaft 26d is fitted in the third rotary shaft 26c.

And, the respective lower ends of the said rotary shafts 26a to 26d aresuccessively deviated in their positions in their vertical direction andare each exposed into the said frame. A timing pulley is fastened toeach such exposed portion. Also, the respective output shafts of fourmotors 27a, 27b, 27c and 27d are coupled to the said rotary shafts 27a,27b, 27c and 27d via four timing belts, respectively. The said motors27a to 27d are disposed around the said rotary shafts 26a to 26d so asto be deviated in their positions within the frame 1a as shown in FIG.12.

Of the above mentioned four motors, the first and second motors 27a and27b constitutes one pair whereas the third and forth motors 27c and 27dconstitute the other pair, the two pairs of motors being rotationallycontrolled, respectively.

More specifically, by permitting the said first and second motors 27aand 27b to rotate oppositely to each other over an identical angle ofrotation, the respective rotations of the said pair of the motors 27aand 27b will be transmitted via a pair of the said timing belts to apair of the said speed reduction gears 25a and 25b, a pair of the saiddisk shaped bosses 23a and 23b, a pair of the said magnetic couplings24a and 24b and a pair of the said ring shaped bosses 20a and 20b,respectively, to rotate the said first and second arms 21a and 21boppositely to each other in their respective directions in which theyapproach each other or in which they depart from each other. If they arerotated in their directions in which they approach each other, the saidtransfer table 8a will be moved so as to be projected. Also, if they arerotated in the directions in which they depart from each other, the saidtransfer table 8a will be operatively moved so as to be sunk orretracted.

When the said pair of the motors 27a and 27b are rotated in an identicaldirection, the said pair of the arms 21a and 21b will be rotated as awhole in one direction or the other.

With the other pair of the motors 27c and 27d, an entirely sameoperation will be performed as with the above mentioned one pair of themotors 27a and 27b. Then, if the other pair of the third and fourth arms21c and 21d are rotated symmetrically or in an identical direction bysaid other pair of the third and fourth motors 27c and 27d, the saidsecond transfer table 8b will be operatively moved so as to be projectedor to be sunk or retracted.

Then, since the said one pair of the first and second arms 21a and 21band the other pair of the third and fourth arms 21c and 21d are spacedapart from each other in their vertical directions, the said one pair ofthe first arms 21a and 21b and the other pair of the third and fourtharms 21c and 21d will be rotationally driven without interfering witheach other.

The respective rotation of each of the above mentioned motors 27a to 27dwill, as noted above, be introduced via a said timing belt and a saidrotary shaft corresponding thereto into the input member of a said speedreduction gear corresponding thereto, where it will be reduced in speedwith a large reduction ratio and then furnished to a disk shaped bosscorresponding thereto. Accordingly, if there is a loosening such as aback-lash due to a said timing belt and if there is a deformation of asaid rotary shaft, an error in the angle of rotation over will over thepath be transmitted after a reduction thereof by the said reductionratio to the output side. Hence, its influence on the latter will bevastly reduced.

Whilst FIGS. 9 to 12 shows an example in which the said motors 27a to27d each of which is coupled to a said rotary shaft correspondingthereto are arranged around the said center of rotation and a saidtiming belt is used as a means for coupling them together, it should benoted that the said motors may alternatively be arranged in series withone another in the direction of the said center of rotation as shown inFIG. 13.

In this case, the first to third motors 27a' to 27c' except the fourthmotor 27d' that lies at the lowest side are so configured as to behollow or to provide three hollow spaces therein into which the saidsecond to fourth rotary shafts 26b and 26d are successively inserted.

In this example, the respective output members 28 of the said motors27a' to 27d' are directly coupled to the said rotary shafts 26a to 26d,respectively.

In a handling robot according to the present invention, it has beenshown that each single transfer table will be operatively moved so as tobe projected and to be sunk or retracted radially with respect thecenter of rotation by one or the other symmetrical rotations of a pairof motors, and will also be rotationally operated by rotating such apair of motors in an identical direction.

And, by way of such a projecting operation as mentioned above, the saidtransfer table 8a and the respective leading ends of the said links 22aand 22b will be projected into any one of the said stations from a saidgate 6 provided in the said partition wall 5 of the transfer chamber 1so that a wafer 29 which comprises a semiconductor blank that has beenmounted on the said transfer table 8a may be carried into the saidstation, as shown in FIGS. 10 and 11.

Also, by way of such a sinking or retracting operation as mentionedabove, the said wafer 29 in the said station will be carried into thesaid transfer chamber 1, and a rotary operation in such a sinking orretracting state will cause the transfer table 8a, 8b to be opposing toa said gate in a preselected station.

Then, since the above mentioned two transfer tables 8a and 8b are spacedapart from each other by a distance S in the vertical direction so thatthey may not interfere with each other when they are rotated asmentioned above, the said gate through which each of them is to bepassed is designed to have such a height of its opening as to enableboth the said transfer table 8a and 8b and both the said link 22a, 22bto be sufficiently passed therethrough.

An above mentioned gate 6 is provided with an opening and closing door6a as mentioned above. The said opening and closing door 6a is designedto perform an opening and closing operation in conjunction with theoperation of the above mentioned transfer tables 8a and 8b, and toremain closed unless it needs to be opened or closed. The said transferchamber 1 is designed to remain in an evacuated state, so is each of thesaid station by a suction unit before the said door 6a is opened.

In the case of a semiconductor manufacturing system, each electricalproperty of a semiconductor must be kept secured with precision by usinga thin film thereof in the order of nanometers. Thus, in itsmanufacturing process, it becomes critical to enhance the quality ofsuch a film in conjunction with the enhancement of the integration andfunction levels of an element. And, if such a film has the molecules ofan unnecessary gas adsorbed thereto, it is altogether possible that thefilm may be deteriorated in its quality and its essential properties andreliability may be seriously lowered.

For this reason, the conveyance of a wafer from the transfer chamber 1to each of the stations has been carried out in an extremely evacuatedstate or under an ultra-high vacuum (or in a high purity gaseousatmosphere that is substantially equivalent to an ultra-high vacuum) forthe purpose of eliminating any influence whatsoever of a residual gas onthe wafer in each of the stations.

It is to this end that, as mentioned above, a said gate 6 of the saidtransfer chamber 1 is provided with a said opening and closing door 6aand is designed to be opened and closed by the said opening and closingdoor 6a in conjunction with the projecting and retracting operations foreach of the said transfer tables 8a and 8b.

The said opening and closing door 6a for an above mentioned gate 6 ismade substantially larger than the area of opening of the said gate 6and is adapted to be thrusted against the said gate 6 to provide such aseal that a gas may not be leaked.

A said gate 6 should better be as small as possible to ensure itsenhanced ability to seal.

In the embodiment of the present invention set forth above, however, itshould be noted that as has been mentioned, in order to enable a pair ofthe said transfer tables 8a and 8b whose positions are deviated in thevertical direction to be passed therethrough, it happens to ensue that asaid gate 6 has an unexpected enlarged area and involves what isdesirable as to its sealability when it is sealed with the said openingand closing door 6a. Also, it should be mentioned that another problemin this connection is that if the area that receives a differentialpressure between the said transfer chamber 1 and any one of the saidstations is enlarged, an actuator that is required to thrust the saidopening and closing door 6a needs to be of an increased output.

In order to resolve these problems, there is provided an arrangement inwhich the said pair of the transfer tables may no longer be passedsimultaneously though a said gate 6 whereby at least one of the saidtransfer tables is rendered displaceable vertically from a position atwhich they do not interfere with each other when they are rotated to aposition of the other of the said transfer tables. Thus, the solution ofthe problems will be the determination of the vertical width of a saidgate 6 to be a width that is just sufficient for only one of the saidtransfer tables to be passed therethrough.

FIG. 14 shows an example of the construction in which the lower transfertable 8a is rendered vertically displaceable so that a pair of the firstand second ring shaped bosses 20a' and 20b' and a pair of the first andsecond disk shaped bosses 23a' and 23b' may be moved as a wholevertically by a distance S' that represents the height of the abovementioned vertical deviation in position.

More specifically, the ring shaped boss 20a' that is located at thelowermost position is rotatably supported by a vertical displacementmember 31 which in turn is supported so as to be vertically displaceableover the above mentioned distance S' via a vertical displacement guidemeans 30 constituted of a linear ball bush, with respect to the saidframe 1a of the transfer chamber 1.

And, above the said first ring shaped boss 20a', there is supported thesaid second ring shaped boss 20b' so as to be rotatable integrallytherewith in the vertical direction.

On the other hand, the said first and second disk shaped bosses 23a' and23b' are constituted as integral with each other in their verticaldirection via a pair of speed reduction gears 25a and 25b disposedinside thereof. A reduction gear fixing member of the said first andlower speed reduction gear 25a and a reduction gear fixing member of thesaid second and upper speed reduction gear 25b are supported and engagedwith each other via a pair of pins 32a and 32b, respectively, in theirrotary direction and so as to be displaceable in their verticaldirection over the above mentioned distance S', each at the side of thesaid frame 1a of the transfer chamber 1.

And, an electrically actuated cylinder 33 that makes use of a linearstepping motor is interposed between the above mentioned reduction gearfixing member of the said first and lower speed reduction gear 25a andthe said frame 1a so that the said member may be displaced vertically bythe said distance S' by means of the said electrically actuated cylinder33.

The respective speed reduction gears 25a and 25b for the above mentionedfirst and second disk shaped bosses 23a' and 23b' have their respectiverotary shafts 26a' and 26b' whose leading ends are engaged with eachother in their rotary direction so as to be slidable via a spline withrespect to the respective output shafts 34a and 34b of a pair of motors27a' and 27b'.

Between the said first and second ring shaped bosses 20a' and 20b' andthe said first and second disk shaped bosses 23a' and 23b', there areprovided, respectively, a pair of magnetic couplings 35a and 35b of alinear rotary type, in place of customary magnetic couplings, whichenable both a force of rotation and an axial force of straightadvancement to be transmitted.

In such a construction as mentioned above, by displacing the saidreduction gear fixing member of the first and lower speed reduction gear25a upwards by means of the said electrically actuated cylinder 33, itcan be seen that the said pair of the ring shaped bosses 20a' and 20b'will be displaced together upwards by the said distance S' so that asaid first transfer table 8a may be displaced upwards via a pair of thesaid arm fastened thereto to reach a level that is identical to that ofa said second transfer table 8b.

Accordingly, by permitting the said first transfer table 8a located atthe lower side to be lifted up to this position when projected into anyone of the said stations, it can be seen that the size of a said gate 6in its vertical direction may be a size which enables only one of thesaid single transfer tables 8a and 8b to be passed therethrough.

At this point it should be noted that whilst only one of the saidtransfer tables is permitted to be displaced vertically in the exampleshown in FIG. 14, it can also be arranged so that both of the said twotransfer tables 8a and 8b may be displaced as a whole vertically.

Several examples of the present embodiment of the invention will beexplained below with reference to FIGS. 15 to 19.

* The example in which the said bosses in a set are vertically moved asa whole (FIG. 15):

The said first, second, third and fourth disk shaped bosses 23a to 23dare arranged so as to be rotatable independently of one another and arecoupled together in an axial direction. Similarly, the said ring shapedbosses 20a to 20d which are opposing to the said disk shaped bosses 23ato 23d, respectively, via the said magnetic couplings of the linearrotary type, are arranged so as to be rotatable independently of oneanother and are coupled together in an axial direction.

The said ring shaped boss 20a and the said disk shaped boss 23a aresupported so as to be slidable axially via a linear guide 30a on a lowercylindrical member 41 that is fastened to a side of the said frame 1a.

Also, the said fourth ring shaped boss 20d and the said disk shaped boss23d are supported so as to be slidable axially via a linear guide 30b onan upper cylindrical member 42 that is coupled to a said partition wall17 which is fastened to the above mentioned lower cylindrical member 41.

Also, since the said speed reduction gears 25a to 25d which are disposedinside of the above mentioned disk shaped bosses 23a to 23d aresupported on the said disk shaped bosses 23a to 23d, they are madecapable of being displaced axially in an integration with the said diskshaped bosses 23a and 23d. Also, the said fixing member of the firstspeed reduction gear 25a is coupled via a bracket 43 to a saidelectrically actuated cylinder 33 that makes use of a linear steppingmotor whereas the respective fixing members of the other speed reductiongears 25b to 25d are each coupled to the fixing member of the said firstspeed reduction gear 25 in their rotary direction. Also, the fixingmember of the said fourth and uppermost speed reduction gear 25d iscoupled to a pin so as to be slidable axially with respect to a cover 44that is integral with the above mentioned upper cylindrical member 42.

On the other hand, the respective input end sides of the said rotaryshafts 26a to 26d which are coupled the respective input members of thesaid speed reduction gears disposed inside of the above mentioned diskshaped bosses, respectively, are engaged with the respective outputsections of the said motors 27a' and 27d', respectively, via foursplines so as to be axially slidable.

In the construction of this example, it can be seen that the said bossesas a whole are vertically displaced by the extension and retractionoperations of the said electrically actuated cylinders 33.

And, by operating, at the both positions, the said motors 27a' and 27b'each in a predetermined manner, it can be seen that each of the saidtransfer tables 8a and 8b will be opposed to a said gate 6 correspondingthereto to perform a predetermined operation.

* An entire boss section containing a drive unit is vertically displaced(FIG. 16):

In this example, a case 46 itself in which the said motors 27a to 27d ofa handling robot A shown in FIG. 9 are received, is supported via alinear guide 45 within the said frame 1a so as to be verticallydisplaceable by the above mentioned stroke S and is adapted to be drivenby a said electrically actuated cylinder 33. It should be noted in thiscase that the said case 46 which is fitted in the said frame 1a so as tobe slidable, is engaged with a pin 1b so that it may not be rotated withrespect to the said frame 1a.

Also, in order to prevent a dust from intruding from the said linearguide portion 45 into the said transfer chamber 1, it is seen that abellows 46a is interposed between the said case 46 and the said frame1a.

* The boss section is vertically displaced by a cam mechanism (FIGS. 17to 19):

A set of the said first to fourth ring shaped bosses 20a to 20d and aset of the said first to fourth disk shaped bosses 23a to 23d are eachrendered axially slidable.

And, a first cam ring 47a is fastened to the output portion of the saidfirst speed reduction gear 25a and a cam follower 50a that is providedfor the said first disk shaped boss 23a via a supporting rod 49a isengaged with a cam slot 48a that is provided in the said cam ring 47a.And, a guide pin 51a that protrudes from the said first cam ring 47a isfitted in the second disk shaped boss 23b so as to be axially slidable.

A second cam ring 47b is fastened to the output portion of the saidsecond speed reduction gear 25b and a cam follower 50a that is providedfor the said second disk shaped boss 23b via a supporting rod 49b isengaged with a cam slot 48b that is provided in the said cam ring 47b.And, a guide pin 51b that protrudes from the said second cam ring 47b isfitted in the first disk shaped boss 23a so as to be axially slidable.

A third cam ring 47c is fastened to the output portion of the said thirdspeed reduction gear 25c and a cam follower 50c that is provided for thesaid third disk shaped boss 23c via a supporting rod 49c is engaged witha cam slot 48c that is provided in the said cam ring 47c. And, a guidepin 51c that protrudes from the said second cam ring 47c is fitted inthe fourth disk shaped boss 23d so as to be axially slidable.

A fourth cam ring 47d is fastened to the output portion of the saidfourth speed reduction gear 25d and a cam follower 50d that is providedfor the said fourth disk shaped boss 23d via a supporting rod 49d isengaged with a cam slot 48d that is provided in the said cam ring 47d.And, a guide pin 51d that protrudes from the said fourth cam ring 47d isfitted in the third disk shaped boss 23c so as to be axially slidable.

As shown in FIGS. 17 and 18, the said first and fourth disk shapedbosses 23a and 23d are each provided with a space 52 through which thesaid guide pin 51a (51d) and the supporting rod 49b (49c) of the saidcam follower pass and which allows them not to interfere with the saiddisk shaped bosses when these bosses are each rotated.

An explanation will now be given with respect to the functions in thisconstruction and the shape of each of the said cam slots 48a and 48bwith reference to FIG. 19.

If the said first cam ring 47a is rotated rightwards by ω 1 via the saidfirst speed reduction gear 25a and the second cam ring 47b is likewiserotated leftwards by ω 1 via the said second speed reduction gear 25b,then the said second disk shaped boss 23b and the first disk shaped boss23a which are coupled thereto via the said guide pins 51a and 51b,respectively, will be rotated rightwards and leftwards, respectively.This will cause the said first and second ring bosses 20a and 20bpositioned outside thereof to be rotated via the said magnetic couplingsof linear rotary type 35a and 35b, respectively, in their respectivedirections in which the said arms 21a and 21b approach each other.

This will in turn cause the said cam follower 50a that is provided forthe said first disk shaped boss 23a to be displaced within the said camslot 48a and then to be lifted up by the distance S and the said camfollower 50b that is provided for the said second disk shaped boss 23bto be likewise displaced within the said cam slot 48b by a predetermineddistance, thereby lifting up both the said disk shaped bosses 23a and23b by the distance S. This will further cause the said first and secondring shaped bosses 20a and 20b to follow the above mentioneddisplacements so as to be lifted up via the said magnetic couplings oflinear rotary type 35a and 35b, thus permitting the said first transfertable 8a to be opposing to a said gate 6 within the said transferchamber 1.

Further, if the said pair of the disk shaped bosses 23a and 23b arerotated by ω 2 and ω 2, the said first and second ring shaped bosses 20aand 20b will be rotated via said magnetic couplings of linear rotarytype, respectively, so that the said transfer table 8a will, whilstmaintaining its height, be moved so as to be projected into a processchamber.

If the said pair of the disk shaped bosses are rotated from this stateby ω 2 oppositely to each other, then the said transfer table 8a will bemoved so as to be sunk or retracted into the said transfer chamber 1.Then, if they are likewise rotated further by ω 1, the said lowertransfer table 8a will be displaced downwards by the above mentioneddistance S so as to deviate in position from the said gate 6.

The said third and fourth cam slots 48c and 48d located upwards and thesaid first and second cam slots 48a and 48b located downwards areoriented in the opposite directions. If the said ring shaped bosses 20cand 20d are rotated by ω 1 via the said speed reduction gears 25c and25d in the opposite directions in which the said arms 21c and 21dapproach each other, the said disk shaped bosses 23c and 23d will bemoved downwards by the above mentioned distance. This will cause thesaid upper transfer table 8b to be displaced downwards within the saidtransfer chamber 1 so as to be opposing to a said gate 6. If they arelikewise rotated further by ω 2, the said upper transfer table 8b willbe projected from the said gate 6 into a process chamber. And, if theyare rotated oppositely to each other, the said transfer table 8b will besunk or retracted in the said transfer chamber 1 whilst being displacedupwards so as to deviate in position from the said gate 6.

* A said transfer table is vertically displaced:

Also, in order to coincide the height of one of the said two transfertables with the height of the other, there may be provided anarrangement, as shown in FIG. 20A, in which an extender and retractorunit 36 that comprises a screw or a cylinder mechanism which is adaptedto extend and retract vertically is provided at a portion at which oneof the said transfer tables 8b is coupled to the said links 22a and 22bof a said transfer table attitude regulating mechanism and the saidtransfer tables 8a and 8b are made identical in level by permitting thesaid unit 36 to be elongated as shown in FIG. 20B.

In the construction in which at least one of the said transfer tables8a, 8b is displaced towards the axial direction of the previouslymentioned center of rotation, it should be noted that in a case wherethere are three or more transfer tables, any arrangement that permitsonly one of them to be displaced will not allow a said gate 6 to beminimized in its height (i. e. to have a height with which only one ofthe said transfer tables is allowed to pass therethrough).

For this reason, there should be provided an arrangement, as shown inFIG. 21, in which each of the said transfer tables 8a. 8b. . . . iscoupled to each of the arms via each of the extender and rectractorunits 36, 36, . . . , respectively, and is displaced thereby so thateach such transfer table may individually be opposing to a said gate 6which is minimized its height.

* A said link is vertically displaced:

In order to allow the above mentioned transfer tables 8a and 8b to bevertically displaced, there may be provided an arrangement, for example,as shown in FIG. 22, in which the said links 22c and 22d are coupled viaa said extender and retractor unit 36a to the respective leading ends ofthe said third and fourth arms 21c and 21d.

In a construction as shown here, reference numeral 55 designates alinear actuator, and reference numeral 56 denotes a linear rotary ballbearing. It can be seen that the said links 22c and 22d will bevertically displaced by the extension and retraction operation of thesaid linear actuator and will allow the said transfer table 8b to bevertically displaced thereby.

FIG. 23 shows another example of the extension and retraction unit forvertically displacing the said links 22c and 22d with respect to theabove mentioned arms 21c and 21d, in which a cam mechanism 57 is used inplace of the said linear actuator 55.

More specifically, a cam shaft 59 is supported via a linear rotary ballbearing 58 by the leading end of the said arm 21c (21d), and the saidlink 22c (22c) is fastened to the leading end of the said cam shaft 59integrally therewith. A pair of cam slots 60 and 60 are symmetricallyprovided on both surfaces of the said cam shaft 59, and are fitted witha pair of cam followers 62 and 62 which are provided in a cylindricalmember 61 that is fastened to the said arm 21c (21d).

A said cam slot 60 and a said cam follower 62 are related to each otherin such a manner that in a terminal state of the operation in which thesaid transfer table 8b is sunk or retracted, it may, when within thetransfer chamber 1, be vertically deviated in position from a said gate6 and that when it is operatively projected slightly from its terminalposition of such a sinking or retracting operation, the said transfertable 8b may be vertically displaced so that the said transfer table 8a,8b can assume the height of the said gate 6 so as to be projected into aprocess chamber immediately before the leading end of the said transfertable 8b reaches the peripheral wall of the said transfer chamber 1. Itshould be noted that this operation is identical for the other transfertable 8a as well.

An explanation has hereinbefore been given with respect to each of avariety of examples of the first embodiment of the present inventionhaving a construction in which a series of the first, second, third andforth ring shaped bosses 20a to 20d each with a drive unit are laid oneabove another to constitute a boss section that is supported on theframe 1a at a bottom side of the transfer chamber 1. It should be notedhere that alternatively, such a boss section may, as shown in FIGS. 24and 25, be divided vertically into a first boss section that iscomprised of the said first and second ring shaped bosses 20a and 20band a second boss section that is comprised of the said third and fourthring shaped bosses 20c and 20d and that the said first boss sectionwhich is lower may be arranged to be opposing to the frame 1a at thebottom side of the said transfer chamber 1 whereas the said secondsection which is upper may be arranged to be opposing to a chamber cover65 for closing the upper side of the said transfer chamber 1, the saidtwo boss sections being disposed coaxially with each other.

According to this alternative example, four drive units are divided intotwo pairs thereof which are located up and down, thus permitting each ofthe drive units to be readily assembled and maintained.

Several constructions of a handling robot A' in each of which the driveunits are divided into two pairs thereof that are located up and downare shown in FIGS. 25 to 29.

* At least one of the two boss sections is vertically displaced (FIGS.25 and 26):

This example corresponds to an arrangement, as shown in FIG. 15, inwhich a boss section as a whole of the bosses is vertically displaced,and represents an example in which the arrangement of FIG. 15 isvertically divided into a lower boss section C1 for driving the saidfirst and second ring shaped bosses 20a and 20b and an upper bosssection C2 for driving the said third and fourth ring shaped bosses 20cand 20d.

FIG. 26 shows the said lower boss section C1 whose construction issubstantially identical to the construction of FIG. 15 in which the saidfirst and second disk shaped boss sections 23a and 23b are driven. Itshould be noted that the reference numeral and characters individuallyand in combination represent the same components or parts.

On the other hand, the said upper boss section C2 has a substantiallysame construction as the construction of the lower boss section that islocated below it, and they are fastened to the said chamber cover 65oppositely to each other.

According to this construction, each of the said transfer tables 8a and8b is vertically displaced by driving a said electrically actuatedcylinder 33 for both the said boss sections C1 and C2 and at the end ofits displacement, it is arranged so as to be opposing to a said gate 6of the said transfer chamber 1.

* Each of the upper and lower boss sections or at least one thereofincluding a drive unit is vertically displaced in its entirety (FIG.27):

This example corresponds to the form of FIG. 16 in which an entire bosssection is vertically displaced, and has a said lower and a said upperboss section C1 and C2, including cases which contain their respectivedrive units, vertically displaced in their entireties, respectively,each by a said electrically actuated cylinder 33, 33. The said bosssections C1 and C2 are arranged so as to be opposing to the said frame1a and the said chamber cover 65 of the transfer chamber 1 downwards andupwards and are vertically displaced by the said electrically actuatedcylinders 33 and 33, respectively. This will allow each of the saidtransfer tables 8a and 8b to be opposing to a said gate 6.

* Each of the upper and lower boss sections or at least one thereof isvertically displaced by a cam mechanism (FIGS. 28 and 29):

This example represents a construction in which the said boss sectionconstructed in a manner as shown in FIGS. 17 to 19 is vertically dividedinto a first boss section comprised of the said disk shaped bosses 23aand 23b and their respective drive units and a second boss sectioncomprised of the said disk shaped bosses 23c and 23d and theirrespective drive units. The drive units for driving the said disk shapedboss 23a to 23d, respectively, are constructed here in an identicalfashion to that in the previous construction, and the same referencenumerals and characters individually and in combination designate thesame components or parts.

According to this construction, the said lower and upper boss sectionsC1 and C2 are vertically displaced each individually by a cam mechanism.

Further, even in the construction here in which the said upper and lowerboss sections divided are provided, there may be no verticaldisplacement of each of the said boss sections C1 and C2. However, aportion of articulation at which a said arm and a said link are coupledtogether may be vertically displaced at the link side by a said extenderand retractor unit 36a or a said cam mechanism 57 as shown in FIGS. 22and 23 described previously. Alternatively, a said transfer table and aportion at which the said transfer table and a said link are coupledtogether may each be vertically displaced by using a displacementmechanism attached thereto.

An explanation will now be given with respect to another embodiment ofthe present invention with reference to FIGS. 30 and 31.

In the explanation of this embodiment as well, it should be noted thatany component or part of the construction thereof which is identical tothat in the construction of the prior art is denoted by the samereference numeral and character individually or in combination and adetailed description thereof will be omitted.

The respective base ends of a first and a second link 120a and 120b arerotatably coupled to the respective leading ends of a said first and asaid second arm 7a and 7b which are projected from a said first and asecond ring shaped boss 10a and 10b radially thereof, respectively. And,the leading end of one link 120a of the said pair of the links 120a and120b is constructed integrally with a transfer table 121 whereas the theleading end of the other link 120b thereof is rotatably coupled at arotary node 122 to the said transfer table 121.

A structure for rotating the above mentioned ring shaped bosses 10a and10b is here identical to that shown in FIG. 5 so that their respectiveangles of rotation may be controlled as desired by a motor unit.

In the construction mentioned above, it can be seen that by rotating thesaid pair of the ring shaped bosses 10a and 10b in their respectivedirections in which the said pair of the arms 7a and 7b approach eachother, the said transfer table 121 will be pushed out by the action ofthe said arms 7a and 7b and the said links 120a and 120b so that it maybe projected from the inside of the said transfer chamber 1 via a saidgate 6 into a desired one of the said stations.

And, if the said pair of the ring shaped bosses 10a and 10b are rotatedfrom this state in their respective directions in which the said arms 7aand 7b depart from each other, the said transfer table 120 will be sunkor retracted into the said transfer chamber 1 and this operation willthen cause a wafer 123 that is mounted on the said transfer table 121 tobe delivered and conveyed over between the said transfer chamber 1 andthe said one station.

Then, since the said transfer table 121 is made structurally integralwith the said one link 12a, the attitude of the said transfer table 121that is both projected and sunk or retracted will be made identical tothe attitude of the above mentioned link 120a. For this reason, therespective angles of rotation θ 1 and θ 2 of the said arms 7a and 7bfrom their reference position for reciprocating the said transfer table121 over between its most sunk or retracted position S1 and its mostprojected position S2 as shown in FIG. 30 are varied from each other.More specifically, the said motor unit is controlled so that the saidrespective angle of rotation θ 1 and θ 2 of the said pair of the arms 7aand 7b from their reference position may be such angles of rotation thatthe said transfer table 121 can be displaced so as to follow atrajectory extending from the said most sunk or retracted position S1 inthe said transfer chamber 1 through the said gate 6 to the said mostprojected position that is a predetermined position in the said onestation.

Then, a method of controlling the said angles of rotation θ 1 and θ 2 ofthe above mentioned pair of the arms 7a and 7b from a said referenceposition will be explained based on the reference symbols shown in FIG.31.

Now, with reference to FIG. 31, if it is assumed that the turning centerof the handling robot is represented by 01, the points at which the saidarms 7a and 7b and the said links 120a and 120b are coupled together,respectively, are represented by 02 and 03, respectively, the point atwhich the one link 120b and the said transfer table 121 are coupledtogether is represented by 04, the center of the said transfer table 121is represented by 05, the said arms 7a and 7b and the said links 120aand 120b have their respective lengths 01-02, 01-03, 02-04 and 03-04which are identical to one another and represented by L, the distancebetween the point 04 at which the said one link 120b and the saidtransfer table 121 are coupled together and the center 05 of the saidtransfer table 121 is represented by Lh and the angle of attitude of thesaid transfer table 121 with respect to the said link 120a that isintegral therewith is represented by θ h, it has been found that theangles of rotation θ 1 and θ 2 of the said pair of the arms 7a and 7bwhich are measured from the said reference position and are required todisplace the said center 05 of the transfer table 121 from the saidturning center 01 of the handling robot over a distance x to a positionthat corresponds to an angle θ from the said reference position areexpressed by the following equations: ##EQU1## where ##EQU2##

If the said transfer table 121 is moved so as to be projected from theinside of the said transfer chamber 1 over the distance x to apredetermined position within a said selected station, it can thus beseen that the motor unit should be controlled so that respective anglesof rotation θ 1 and θ 2 may meet the above identified equation.

If the said pair of the arms 7a and 7b are rotated in an identicaldirection in the state in which the said transfer table 121 has beensunk or retracted, the said transfer table 121 will be operativelyturned in the said transfer chamber 1 so as to be opposing to another ofthe said stations.

Whilst in the above mentioned embodiment the said transfer table 121 isconstructed so as to be structurally integral with the said one link120a, this is, of course, not a limitation. Thus, alternatively, thesaid transfer table 121 and the said link 120a may be made separatelyand then be coupled together by a bolt or the like so as to be integralwith each other.

As set out in the foregoing description, it will be appreciated that bypermitting the said transfer table 121 and the said pair of the links120a and 120b to be coupled together at a single rotary node 122, a dustcan be extremely much less frequently produced in the present inventionas compared with the prior art in which the two rotary nodes has beenrequired as in the transfer table attitude regulating mechanism B shownin FIGS. 4A and 4B and a gear or belt coupling has been essential. Inaddition, with the number of rotary nodes being reduced to only one,there can be no loosening adversely influencing on an operation of thehandling robot according to the present invention, which has nototherwise be avoidable with the two rotary nodes which have beenessential in the prior art.

While the present invention has hereinbefore been described with respectto certain illustrative embodiments thereof, it will readily beappreciated by a person skilled in the art to be obvious that manyalterations thereof, omissions therefrom and additions thereto can bemade without departing from the essence and the scope of the presentinvention. Accordingly, it should be understood that the presentinvention is not limited to the specific embodiments thereof set outabove, but includes all possible embodiments thereof that can be madewithin the scope with respect to the features specifically set forth inthe appended claims and encompasses all equivalents thereof.

What is claimed is:
 1. A handling robot, characterized in that:at leastfour bosses are disposed in a transfer chamber so as to be coaxial toone another and rotatable independently of one another and to bedeviated in their positions towards the axis of a center of rotation;each of said bosses is provided with an arm, respectively; a link iscoupled to each of such arms, respectively; two of said bosses which areadjacent to each other in an axial direction are constituted in a pair;a transfer table is coupled via a transfer table attitude regulatingmechanism to the respective leading ends of each pair of such linkswhich are in turn coupled to each arm of said each pair of the bosses toprovide a plurality of such transfer tables which are arranged so as tobe deviated in their positions towards said axis of the center ofrotation; and an independent drive source is coupled to each of saidbosses, respectively.
 2. A handling robot, as set forth in claim 1,characterized in that:a first boss section that comprises a first pairof said bosses arranged in said axial direction and a first pair ofdrive units coupled respectively to said bosses is separately configuredfrom a second boss section that comprises a second pair of said bossesarranged in said axial direction and a second pair of drive unitscoupled respectively to said bosses; said first and second boss sectionsare arranged so as to be opposing to each other and in such a mannerthat said bosses may be made coaxial to one another; and said pluralityof the transfer tables are arranged between said first and second bosssections so as to be deviated in their positions towards said axis ofthe center of rotation.
 3. A handling robot, as set forth in claim 2,characterized in that:a said boss section including a said drive unit issupported so as to be displaceable towards said axis of the center ofrotation with respect to a frame of said transfer chamber; and a linearactuator is coupled to said boss section.
 4. A handling robot, as setforth in claim 2, characterized in that:at least one of said first bosssection and said second boss section is supported so as to bedisplaceable towards said axis of the center of rotation with respect toa frame of said transfer table; and a linear actuator is coupled to saidat least one boss section.
 5. A handling robot, as set forth in claim 2,characterized in that:inside of said bosses which are ring shaped, thereare different bosses which are disk shaped and are supported by a frameof said transfer chamber so as to be each rotatable; each of said diskshaped bosses and each of said ring shaped bosses are coupled togethervia a magnetic coupling so as to be coupled and decoupled with eachother in a rotary direction; each of said disk shaped bosses is providedinside thereof with a speed reduction gear; said reduction gear that isprovided inside of each such disk shaped boss has an input memberthereof to which is coupled a rotary shaft, respectively; such rotaryshafts are arranged so as to be coaxial about said center of rotationand so as to extend towards one side of said axis of the center ofrotation; and each of said rotary shafts is coupled to a motor,respectively.
 6. A handling robot, as set forth in claim 2,characterized in that:at least one pair of said bosses which are ringshaped and said drive unit for driving said ring shaped bosses arerendered capable of being displaced towards said axis of the center ofrotation.
 7. A handling robot, as set forth in claim 2, characterized inthat:at a section at which a said transfer table and a said link coupledto said transfer table are coupled together, there is provided adisplacement mechanism for displacing said transfer table towards saidaxis of the center of rotation with respect to said link.
 8. A handlingrobot, as set forth in claim 2, characterized in that:at a section atwhich a said link and a said arm are coupled together, there is provideda displacement mechanism for displacing said link towards said axis ofthe center of rotation with respect to said arm.
 9. A handling robot, asset forth in claim 2, characterized in that:at a section at which a saidlink and a said arm are coupled together, there are provided a cam shafthaving a cam portion and a cam engagement member fitted with said camportion so that they may be coupled to one of said link and said arm;and said cam portion is so configured that when each pair of said armsare rotated in their respective directions which are opposite to eachother, said pair of the links may be displaced towards an axiallyidentical direction.
 10. A handling robot, as set forth in claim 1,characterized in that:at a section at which a said link and a said armare coupled together, there is provided a displacement mechanism fordisplacing said link towards said axis of the center of rotation withrespect to said arm.
 11. A handling robot, as set forth in claim 1,characterized in that:inside of said bosses which are ring shaped, thereare different bosses which are disk shaped and are supported by a frameof said transfer chamber so as to be each rotatable; each of said diskshaped bosses and each of said ring shaped bosses are coupled togethervia a magnetic coupling so as to be coupled and decoupled with eachother in a rotary direction; each of said disk shaped bosses is providedinside thereof with a speed reduction gear; said reduction gear that isprovided inside of each such disk shaped boss has an input memberthereof to which is coupled a rotary shaft, respectively; such rotaryshafts are arranged so as to be coaxial about said center of rotationand so as to extend towards one side of said axis of the center ofrotation; and each of said rotary shafts is coupled to a motor,respectively.
 12. A handling robot, as set forth in claim 11,characterized in that:such motors are disposed in series with oneanother in the direction of said axis of the center of rotation of saiddisk shaped bosses; and each of said motors has an output member thereofthat is directly coupled to each of said rotary shafts, respectively.13. A handling robot, as set forth in claim 11, characterized inthat:each of a said ring shaped boss and a said disk shaped boss whichare opposing to each other via said magnetic coupling is renderedcapable of being displaced towards said axis of the center of rotation;a pair of boss sections of said disk shaped bosses which are adjacent toeach other in said axial direction are coupled together by a said speedreduction gear; a cam ring is provided coaxially with each of said diskshaped bosses of said boss sections; a cam engagement member that isprovided for each of said disk shaped bosses is engaged with a camportion that is provided in said cam ring; and said cam is configured sothat when said pair of the disk shaped bosses are rotated oppositely toeach other, they may be displaced as a whole towards said axialdirection.
 14. A handling robot, as set forth in claim 11, characterizedin that:a pair of said ring shaped bosses which are coupled to at leastone of said plurality of the transfer tables and a pair of said diskshaped bosses which are positioned inside of said pair of the ringshaped bosses are each supported so as to be displaceable towards saidaxis of the center of rotation; each of said ring shaped bosses and eachof said disk shaped bosses which are opposing to each other are coupledtogether by a magnetic coupling such as that of a linear rotary typewhich is made capable of transmitting both a force of rotation and aforce of straight advancement in an axial direction; and said insidepositioned pair of the disk shaped bosses are coupled to a linearactuator for displacing said pair of the disk shaped bosses.
 15. Ahandling robot, as set forth in claim 11, characterized in that:suchmotors are disposed in parallel to one another around said center ofrotation of said disk shaped bosses; and each of said motors and each ofsaid rotary shafts are coupled together by a power transmission meanssuch as a timing belt.
 16. A handling robot, as set forth in claim 1,characterized in that:at least one pair of said bosses which are ringshaped and said drive unit for driving said ring shaped bosses arerendered capable of being displaced towards said axis of the center ofrotation.
 17. A handling robot, as set forth in claim 1, characterizedin that:at a section at which a said transfer table and a said linkcoupled to said transfer table are coupled together, there is provided adisplacement mechanism for displacing said transfer table towards saidaxis of the center of rotation with respect to said link.
 18. A handlingrobot, as set forth in claim 1, characterized in that:at a section atwhich a said link and a said arm are coupled together, there areprovided a cam shaft having a cam portion and a cam engagement memberfitted with said cam portion so that they may be coupled to one of saidlink and said arm; and said cam portion is so configured that when eachpair of said arms are rotated in their respective directions which areopposite to each other, said pair of the links may be displaced towardsan axially identical direction.
 19. A handling robot, as set forth inclaim 1, characterized in that:at least one of said plurality of thetransfer tables is rendered capable of being displaced towards said axisof the center of rotation.